Effect of Probiotics on Interleukin 6 and Transforming Growth Factor-βLevels in Critically Ill Children With Sepsis

Sepsis, defined as an infection with deregulated host response leading to life-threatening organ dysfunction. Historically, the term sepsis has been used to characterize life-threatening infections usually caused by bacterial pathogens if untreated progress to shock and death, It contributes to 19% of all deaths globally, with the highest age-specific incidence in children younger than 5 years of age. Pediatric sepsis resulted in 0.7% of all hospital encounters. Epidemiologic studies found an incidence of pediatric sepsis in up to 8% of all pediatric intensive care unit (PICU) admissions, contributing to 1in 4 deaths in PICUs.

Despite many advances in diagnosis and management, sepsis is associated with significant morbidity and mortality in pediatric population. The pathophysiology of systemic inflammatory response syndrome (SIRS)and sepsis is characterized by hyperactive and deregulated endogenous inflammatory mediators in a sequential manner resulting in a cytokine cascade.

Cytokines are regulators of the immune response to infection and play a key role in regulating inflammation and trauma. There are two types of cytokines. Pro-inflammatory cytokines and anti-inflammatory cytokines.

Pro-inflammatory cytokines(tumor necrosis factor [TNF]-α, interferon-γ, interleukin[IL]-1α, IL-1β, IL-6, IL-8, IL-12, IL-17) are important for initiation of an effective inflammatory response against pathogens, whereas their excess production can lead to multiple organ dysfunction syndrome (MODS) and mortality, on the other side, anti-inflammatory cytokines (IL-4, IL-10, IL-13,transforming growth factor [TGF]-β) are required for controlling and down-regulating the inflammatory response and if severe can lead to depression of the immune system.

The levels of these cytokines rise within few hours of onset of sepsis and remain elevated for days together depending on severity and duration of sepsis, baseline host factors, timing of sampling relative to onset of sepsis/septic shock, and inter-individual variation.